Exploration of crystal field level scheme of Ti doped Tb2Zr2O7

We are investigating the Tb₂Zr₂₋ₓTiₓO₇ (TZTO) compounds, where Ti doping transforms the structure from a disordered fluorite to an ordered pyrochlore phase. Our recent bulk measurements reveal new structural and magnetic features in Tb₂Zr₂₋ₓTiₓO₇. Heat capacity measurements (Fig. 2(a)) show a peak
near 4.9 K at zero field, which remains in the Ti-doped sample but with reduced intensity. . AC susceptibility of Tb₂Zr₂O₇ also shows a notable deviation at 4.9 K, which weakens above 1 T. Beyond this field, a spin-freezing-like feature appears, similar to that observed in Dy₂Zr₂O₇ and Ho₂Zr₂O₇. These results suggest that changes in structure significantly alter the magnetic ground state and likely impact crystal electric field (CEF) excitations. We propose to perform inelastic neutron scattering measurements in Tb₂Zr₂₋ₓTiₓO₇ (x = 0, 0.50) to understand the 4.9 K anomaly and role of CEF excitations on the magnetism of the compound using the high count-rate chopper spectrometer MERLIN. We request 1 day of beamtime to collect data at three temperatures 4 K (or below), 10 K, and 100 K, for 7 hours and the additional time 3 h for cooling/warming.